The protease inhibitor class of drugs is important for the long-term clinical outcome of HIV infected subjects. Given the recognized difficult in achieving virologic suppression in individuals who have been experienced virologic failure, this study has been designed with the purposes of a) providing maximally potent complex regimes utilixing combinations of currently approved protease inhibitors and experimental agents drawn from protease inhibitor (Amprenavir), nucleoside (abacavir), nucleotide (adefovir) and non-nucleoside (efavirenz) reverse transcriptase inhibitor classes of agents; b) investigating the salvage potential of mprenavir in dual protease inhibitor containing regimes; c) determining if the potential for salvage is greater if a moderately liberal definition of virologic failure (ie., 1,000 copies/ml plasms HIV rna) is employed and d) determining if a strict definition of virologic success in the setting of protease inhibitor failure (i.e, achieving plasma HIV-1 rna levels <200 copies per ml) is realistic with the therapeutic agents on the immediate horizon.